Water adsorption-desorption isotherms of two-dimensional hexagonal mesoporous silica around freezing point

► Zr-MPS could adsorb water vapor without freezing at 263 K. ► The relative pressure of capillary condensation changes in consecutive measurements. ► The relative pressure of capillary evaporation depends on temperature. ► The curvature radii during capillary condensation and evaporation were elucidated.